1. Field of the Invention
The present invention relates to mounting means for plate cylinders of a printing machine, preferably a flexographic printing machine, having replaceable sleevelike plate cylinder shells. More particularly, the present invention relates to structure to permit the rapid removal and replacement of plate cylinder shells without removing the plate cylinder core from the printing machine.
2. Description of the Prior Art
To permit rapid changeover of a flexographic printing machine from one printing job to a new printing job, it is known to provide a tapered plate cylinder core, with a slidably fitted sleevelike plate cylinder shell, so that only the shell is replaced by a new one for a different printing job. For such a replacement of the sleevelike plate cylinder shell, only one bearing of the plate cylinder is removed so that the sleevelike plate cylinder shell can be axially pulled from the plate cylinder core and a new plate cylinder shell can be axially slidably fitted on the core. During such replacement of the shell sleeves it is usually necessary to remove one bearing or to disassemble one bearing to such an extent that the journal of the plate cylinder core carried in the bearing is disengaged from the bearing. A supporting tube is then usually slidably fitted on the plate cylinder core journal and is carried on a bracket so that the plate cylinder core will not fall down, because it is only mounted in a bearing at one end of the cylinder core. The shell sleeve that has been slidably removed from the cylinder core is then initially disposed on the support tube that extends from and supports the plate cylinder core, and the shell sleeve must then be removed from the support tube before the new plate cylinder sleeve can be pushed onto the plate cylinder core. As the shell sleeve is removed from the plate cylinder core and is moved onto the support tube, the plate cylinder core must be held in a substantially horizontal position. That known method of replacing the plate cylinder sleeves is relatively complicated and time-consuming.
In a plate cylinder core mounting arrangement of the kind hereinabove described and disclosed in German Patent Specification No. 891,396, the bearing bracket consists of a conical disc and is held by clamping elements in a complementary conical opening formed in the wall of the machine frame. For this reason the detaching and fixing of the bearing bracket of the known mounting means are relatively time-consuming operations.
It is an object of the present invention to overcome the problems resulting from the known mounting arrangement and to provide a mounting structure that permits a simpler and quicker replacement of the sleevelike plate cylinder shell in a printing machine.